Study of the extraction of proanthocyanidins from grape seeds

The extraction of proanthocyanidins was studied in the system ethyl acetate–water–grape seeds. It was found that, in the absence of water, proanthocyanidins could not be practically extracted, and the increase in water content in the system up to the saturation level resulted in a substantial yield enhancement. It was also shown that ethyl acetate, with 10% of water, is capable of selectively extracting proanthocyanidins, which has not been the case with solvents used previously. This solvent mixture extracts mainly the proanthocyanidins of lower molecular masses, which are more important from a therapeutic point of view. A further increase in water content in the extraction system yielded a small increase in the yield of proanthocyanidins, but caused a decrease in selectivity of the extraction.